A jumping, ball-like robot powered by steam sounds like something out of a steampunk fantasy, but could be the ideal way to explore some of the distant, icy environments of our solar system.
That is the idea behind NASA's new robot concept, the Steam Propelled Autonomous Retrieval Robot for ocean worlds or SPARROW. This round robot would be the size of a football with instruments in the middle of a metal cage, and would use steam-powered engines to jump from one area to the next.
As crazy as it sounds, it actually makes sense to use steam instead of rocket fuel, as this would not contaminate the areas through which the robot drives. This makes SPARROW suitable for exploring icy environments such as Jupiter's moon Europa or Saturn's moon Enceladus, which are believed to have a fluid ocean under an icy crust and may be some of the places in our solar system that are most likely to support life.
In this artist's concept, a steam-powered SPARROW robot jumps away from its home base to explore the surface of an icy moon. NASA / JPL-Caltech
"The terrain in Europe is likely to be very complex," said Gareth Meirion-Griffith, JPL robotics and lead researcher on the concept. “It could be porous, it could be covered with crevasses, there could be meter-high penitentes (long ice blades that could be dangerous for ground-based vehicles) that would stop most robots in their tracks. But SPARROW has total terrain agnosticism; It has complete freedom to travel through an otherwise inhospitable area. "
To find out how to navigate in this complex terrain, the JPL team conducted computer simulations to see how a spherical robot could move over uneven ground and what would happen if it returned to the ground after jumping up. They found that the robot can move most efficiently if it uses large, giant hops instead of smaller ones. "From these and related drive calculations, we found that a single long jump was more efficient than multiple smaller jumps," said Meirion-Griffith.
The SPARROW concept is still under development. The next step is to apply for Phase II funding under NASA's Innovative Advanced Concepts program, which aims to promote visionary new ideas for exploring the solar system and beyond.